This invention pertains to video switching and, more particularly, to a method of switching between two video signal sources to a video utilization device employing digital techniques.
In present television presentations, there has become a greater demand for special effects. One common special effect is the transition from one thematic sequence to another. At a very rudimentary level, merely when one theme is over, there is an immediate switch to the next theme. However, to enhance the viewability of the program, techniques such as horizontal and vertical wipes are employed, i.e., there is a gradual change across the screen from one scene to another. Heretofore, these techniques utilized a technician-operated joystick to create voltages for controlling the switching. Such techniques limited the types of transitions which could be performed and also relied on the skill of the operator.